I want to display a 2d image in a buffer then onto screen

Question

Hi!
I was wondering does anyone know how to draw an image first into a buffer
and then when desirable onto the screen.
so for example in class A there is a method:
void setContrast(float contrast)
contrast = contrast;
repaint;
}and then in class B i want to paint first into a buffer for a given contrast and then onto the screen when i want.
any ideas?

Answer 1

the problem is, my paint method has to be as follows:
and it is in a class called class A.
//in class A
public void paint(Graphics g)
super.paint(g);
Graphics2D g2D = (Graphics2D) g;
for(j=0; j<size; j=j+2)
  for(k = 0; k<size; k=k+2)
   g2D.setPaint(new Color(contrast, contrast, contrast));
   Rectangle2D r2 = new Rectangle2D.Float(j, k, 2, 2)
   g2D.fill(r2)
}the contrast is set through class B calling setContrast(float contrast) which is a method in A
public void setContrast(double c)
contrast =c ;
repaint();
}in this case, how would i do it? and then to display the image in class B?
thanks!!